Abstract: In a forward-looking infared system of the type in which a cryogenically led infared detector array drives a light-emitting array whose video output is focused onto the target of an electro-optical multiplexer, such as a vidicon tube, which drives a CRT display, the video chain may be tested without cool-down of the infared detector. A point-source of light, such as a tungsten lamp mounted forward of and at the side of the vidicon target, is energized to project light onto the target surface at an acute angle, setting up a gradient of light intensity across each of the horizontally scanned lines.

Abstract: A novel prestored area correlation tracker comprising multiple concentric field of view apparatus in combination with apparatus for memorizing multiple digital representations of a target scene and logic apparatus to utilize such representations for the purpose of recognizing said target scene and accurately maintaining a desired aim point in the scene. A primary embodiment utilizes a small field of view apparatus in conjunction with self made direct view memories for tracking the target scene during range closure, and a large field of view apparatus in conjunction with the previously stored memories for initial pointing and intermediate corrections of the afore-mentioned tracking, with said small field of view tracking minimizing the number of prestored memories required for intermediate corrections.